Update flow chart

src/tools/backend/flow.fig

@@ -117,7 +117,6 @@ Inches
 4 1 -1 0 0 28 18 0.0000 4 195 1470 5685 2190 Postmaster\001
 4 1 -1 0 0 28 18 0.0000 4 240 1110 9585 3375 Postgres\001
 4 1 -1 0 0 28 18 0.0000 4 240 1110 5700 3390 Postgres\001
-4 1 -1 0 0 28 18 0.0000 4 240 915 9600 5970 Simple\001
 4 1 -1 0 0 28 18 0.0000 4 195 1980 5685 7455 Generate Paths\001
 4 1 -1 0 0 28 18 0.0000 4 195 1275 5715 7170 Rewrite &\001
 4 1 -1 0 0 28 18 0.0000 4 255 1500 5715 6090 Traffic Cop\001
@@ -125,7 +124,6 @@ Inches
 4 1 -1 0 0 28 18 0.0000 4 195 1485 9600 6255 Commands\001
 4 1 -1 0 0 28 18 0.0000 4 195 1830 5715 8670 Generate Plan\001
 4 1 -1 0 0 28 18 0.0000 4 195 1890 5700 8400 Choose Path &\001
-4 1 -1 0 0 28 18 0.0000 4 240 900 7605 5925 simple\001
 4 1 -1 0 0 28 18 0.0000 4 240 1125 5715 6660 complex\001
 4 0 -1 0 0 0 24 0.0000 4 330 1290 600 1470 Program\001
 4 0 -1 0 0 0 24 0.0000 4 255 735 600 1890 Flow\001
@@ -138,3 +136,5 @@ Inches
 4 1 -1 0 0 28 18 0.0000 4 195 1140 5685 9720 Executor\001
 4 0 -1 0 0 0 18 0.0000 4 255 645 9225 2175 Libpq\001
 4 0 -1 0 0 0 18 0.0000 4 255 840 1050 6675 Catalog\001
+4 1 -1 0 0 28 18 0.0000 4 240 795 7605 5925 utility\001
+4 1 -1 0 0 28 18 0.0000 4 240 825 9600 5970 Utility\001